1888.] Lt.-Col. J. Waterhouse— Ow tlie Barisdl Guns. 105 



They appear to be lieard more distinctly after rain or in the lull 

 after a squall, but are also recorded as occurring before rain. 



Several theories have been brought forward to account for these 

 sounds, and among them the principal are : 



(I.) The breaking of enormous surf rollers on the shores of the 

 upper part of the Bay of Bengal ; the sound of this travelling inland 

 along the surface of the rivers, and to long distances under the favour- 

 able atmospheric conditions of the S. W. Monsoon. 



(II.) The breaking down of the banks of the rivers in the vicinity 

 of places where they are heard. 



(III.) The firing of bombs or guns on the occasion of marriages. 



(IV.) Subterranean or sub-aqueous volcanic or seismic agencies. 



(V.) Atmospheric electricity. 

 Also by the bursting of bamboos or the falling of trees in the jungles. 

 The evidence hitherto recorded, however, in support of these possible 

 causes is altogether insufficient to warrant our attributing the sounds to 

 any one of them. 



It is evident that the first theory is dependent upon the proximity 

 of the places where the sounds are heard to the sea coast or to rivers 

 along which the sound could be carried. 



Now we find that they are heard in nearly all parts of the Gangetic 

 delta, a tract of almost absolutely flat country bordering the extreme 

 north-western corner of the Bay of Bengal, extending from the Hughli 

 to the Megna, and intersected by innumerable streams and water-courses. 

 They appear to be most common along the course of the Megna, but 

 have also frequently been heard along the course of the Haranghatta 

 about the middle of the Delta. 



Babu Gaurdas Bysack records that at Bagirhat, on a tributary 

 of the Haranghatta at a distance of about 56 miles from the open sea, 

 they are heard at all times of the year, particularly when the weather is 

 calm and the sky clear. They are most distinct after a storm or heavy 

 shower of rain. 



At Barisal, on the Baleswar River, about .34 miles from the sea, they 

 are equally prominent, and are heard all over south Jessore and Bakar- 

 ganj, at least in the neighbourhood of the Baleswar River, and extend- 

 ing to the foot of the Chittagong Hills. Mr. Pellew, who has given a 

 good deal of information about them, sajs he has not heard them himself 

 west of Morellgunj on the Haranghatta, about 42 miles from the sea, 

 though Mr. Rainey has recorded them at Khulna, which is situated at 

 the confluence of the Bhairab and Rupsa rivers, about 60 miles from the 

 gea. 



Babu Gaurdas Bysack has, however, recorded the curious fact that 



